The present invention pertains generally to electronic appliances, and more particularly to a method and apparatus for allowing appliances which communicate via infrared technology to automatically enter a receive mode when powered up.
The increasing use of portable computing appliances means that a user may store and work on data files on a fixed desktop computer at his workstation on site, and take a personal computing appliance such as a portable or palm top computer with him for use off-site. Data is typically transferred between the desktop appliance and the personal computer-appliance via a cable or a close range infrared (IR) link. The wireless access provided by electronic appliances allows greater flexibility and convenience.
The built-in infrared communications ability of electronic appliances allows direct short distance communication. However, the current state of infrared communications between appliances remains problematic. First, prior art appliances require a user interface such as a dedicated button that allows the user to place the appliance in a receive mode in order to allow it to receive input from other appliances. Due to the increased market for greater portability and therefore smaller devices, it would be desirable to condense or eliminate the need for a user interface associated With placing the device in a receive mode in order to receive input from other devices. In addition, the method for placing the device into receive mode is often not intuitive and requires the user to refer to an instruction manual and commit the process to memory. It would be desirable to eliminate the need on the part of the user to manually place the appliance into receive mode. Second, if the receive mode user interface malfunctions in prior art devices, there is typically no way for the appliance, which may otherwise function normally, to receive input. This makes it inconvenient for users desiring non-critical input from other devices, and crucial for users: needing critical input from other devices. Furthermore, a malfunctioning receive mode user interface makes it difficult for technical support engineers to run diagnostics on the appliance when it is not working properly. Finally, prior art appliances typically need to be powered all the time in order to receive potential incoming communications from other appliances. To accomplish this, many devices provide a xe2x80x9csleepxe2x80x9d mode which places the device in the lowest possible state of power consumption while still powering the receive circuitry. Nonetheless, the requirement of supplying continuous power in a portable battery powered appliance results in a high battery-replacement factor, which is not only expensive, but often can result in the appliance not functioning when a critical communication is received. Thus, it would be desirable to have an alternative method for conserving power in portable battery-powered appliances.
Accordingly, a need exists for an improved receive mode for appliances that communicate via an infrared port.
The present invention is a novel automatic receive mode for infrared devices. By automatically entering a receive mode when powered up, an appliance implemented in accordance with the invention no longer requires a user interface associated with placing the device in a receive mode, thereby reducing or eliminating user interface space and complexity. In addition, by eliminating any user interface associated with placing the appliance into a receive mode, the invention eliminates any user intervention required to place the device into receive mode, thereby simplifying the operation of the device by the user. Because appliances implemented in accordance with the invention automatically enter receive mode upon power up, this both eliminates any receive problems associated with malfunctioning of a user interface as in prior art appliances, and also allows technical support engineers to run diagnostics on the appliance when it is not working properly if the device is capable of receiving and processing diagnostic commands through this interface. Finally, the automatic receive mode upon power-up provides a simple method for conserving power in battery powered applications. The appliance simply remains off unless the user knows a communication is about to be received. When an appliance is ready to send a communication to another appliance, the other appliance is powered on, automatically enters receive mode for a predetermined period of time, receives the communication if one is received within the predetermined period of time, and then acts on the communication in accordance with the functional purpose of the particular appliance. Thus, the invention provides a simple method for conserving power in portable battery-powered appliances.
In accordance with the invention, a battery-powered electronic appliance comprises a communications interface including receive mode circuitry and a battery that supplies power to the receive mode circuitry when the receive mode circuitry is enabled. Upon power up, the communications interface is initialized, and the receive mode circuitry is enabled to operate in a receive mode for a predetermined amount of time. A timer times the predetermined amount of time. If the timer expires, the receive mode circuitry is disabled to remove power from the receive mode circuitry, thereby conserving battery power in the device. Preferably, if the predetermined enable time expires while the receive mode circuitry is currently receiving input, the predetermined enable time is extended by an extension time, and the timer is restarted, with this process repeating until the receive mode circuitry is no longer receiving input. In a preferred embodiment, the receive mode circuitry is re-enabled periodically after a predetermined disable time, and the timing process is repeated, causing the receive mode circuitry to be disabled again if data is not received within the predetermined enable time.